Catheters that provide fluid communication with the small intestine of a patient are typically employed for supplying nutriment to a patient during a period of post-operative recuperation. The catheter may be inserted into the small intestine via a percutaneous route, i.e. through the abdominal wall, or may alternatively be inserted nasally. Once the enteral feeding catheter is properly deployed, it may remain in position for supplying nutriment to the patient for as long as six or seven weeks. Thus, enteral feeding via a catheter in this manner is not only considerably easier to administer than intravenous nutriment supply, but is also significantly less expensive.
Naso-intestinal catheters for conveying nutriment to the small intestine are typically inserted into the jejunum via a previously deployed stomach probe. The stomach probe is designed to extend into the stomach of the patient and defines a lumen through which insertion of the jejunal probe is guided. Thus, the stomach probe has a larger diameter than the jejunal probe and, even with the jejunal probe extending through it, the lumen of the stomach probe is typically formed large enough to define a space around the feeding probe for evacuating or draining gastric fluids from the stomach during nutriment supply to the patient via the feeding probe.
Stomach probes typically have a length in the range of about 1000 mm to 1200 mm, whereas feeding probes are typically somewhat longer (e.g. 1600 mm to 2000 mm) such that they emerge from and extend beyond the stomach probe into the small intestine. When inserted through the lumen of the stomach probe, an outer surface of the feeding probe will typically be in contact with an inner surface of the lumen of the stomach probe over much of their common length. This has a number of disadvantages, including frictional resistance which may hinder deployment of the feeding probe.
In this regard, it is to be appreciated that deployment of a feeding probe through a stomach probe involves sliding a soft, flexible, small-diameter catheter along a convoluted path through the cavities of the nose, throat and oesophagus. Given the soft and flexible nature of the feeding probe, as well as a small outer diameter of only a few millimeters, it will be understood that frictional resistance between the outer surface of the feeding probe and an inner surface of the lumen in the stomach probe may complicate the insertion process. To assist in this regard, a guidewire is often employed. Furthermore, as the stomach probe is typically provided with lateral openings at its distal end region for effecting decompression and/or drainage of the stomach during the enteral feeding procedure, contact between the feeding probe and the inner surface of the stomach probe lumen may also partially block the lateral drainage holes, thereby causing a sub-optimal performance of the stomach probe.
During deployment of an enteral feeding probe, the progress of the probe into the small intestine is often monitored using an endoscope. The endoscope illuminates the site within the patient and generates video images of the probe as it is advanced towards its desired position. The progress of the probe may then be observed on a video monitor by the medical professional inserting the probe. A problem with this technique, however, is that known jejunal probes are difficult to observe under the illumination provided by many endoscopes.
Furthermore, as the small intestine is a dynamic environment subject to peristaltic movements as well as to influences of the patient moving his/her body, it is important to ensure that, once deployed, the jejunal probe remains in the desired position.
In view of the above considerations, the present invention is concerned with providing a catheter and a catheter system for deployment in the stomach and/or in the small intestine of a patient which provides for an improved inter-operability between a stomach probe and a feeding probe. The invention is also concerned with providing improved visibility of jejunal probes during observation with an endoscope. In addition, the invention aims to provide a catheter having a greater capability of maintaining its position once deployed in the small intestine.